Stop Googling
1:5000 is a 0.02% risk that your baby has DS. That means you have a 99.8% risk of having a baby without DS. Does that help calm you down a bit looking at it like that? If someone told you your chance of winning the lottery was 99.8% you'd be pretty happy right?
By the time you get into the thousands, the difference between results is negligible anyway (eg a 1:5000 risk is 0.02% and a 1:10,000 is a risk of 0.01% - sure, it's half the risk, but it's actually a tiny tiny change). Of course you could be that one in either scenario, but it's unlikely.
The reason you got a higher risk than others (although it's still tiny) is either due to your bloods (a bit higher/lower than theirs) or the nuchal measurement (a bit bigger) since the results are combined in some fancy formula. Assuming the baby is healthy, the former are just what's normal for you (see below - I have 'bad' bloods so mine suggest a problem even when there isn't one - that's just how I respond to pregnancy!) and the nuchal measurement depends a lot on the sonographer: someone else may well have measured differently (our NHS sonographer got 2.3mm for us, and then the private scan a week later got 1.9mm - go figure...) - just like the baby's size. It's negligible differences in the end.
Despite all this, your NT sounds perfect: just right for a healthy baby.
My results with my first baby at 28 were 1:3000, and then with this one (at 30) we initially got 1:90. The NHS were super keen for me to have an amnio and to discuss 'possible next steps' (ie termination) but we refused (and were quite offended by their pushiness): we had a risk of just over 1%, which was still tiny (plus we'd wouldn't abort just because our baby wasn't 100% healthy). We paid for a private scan however to help prepare us if our baby is disabled which looked at more factors than just bloods and nuchal and our risk went down to 1:3000 again (as mentioned, I have 'bad' blood which skews my risk factor when only it and the nuchal are taken into account).
Ultimately, however low your risk, there is no guarantee that your baby does not have DS unless you are willing to have an amnio. But then a) your risk of miscarriage with an amnio is arguably higher than your (personal) risk of having a DS baby (depends on the skill of the person doing the procedure) and b) would you terminate a DS baby? If not, you need to think about whether or not the amnio is worth it.
Pregnancy is a big step into the unknown - from the gender, to the appearance, to the health of the baby, as well as the changes to you, it's all unknown and can be really scary. But you need to learn to relax: DS isn't the only health problem your baby could have, and if you worried about every single possible problem you'd go crazy. Sometimes we can have too much knowledge.
Sorry for the essay - hope it's helped to calm you down a bit.
